The Republic of the Sphere viewed the nascent Marik-Stewart Commonwealth as the greatest threat to the Republic within the boundaries of the former Free Worlds League, as the Army of the Marik Commonwealth (later the Army of the Marik-Stewart Commonwealth) was rebuilding quickly with combat-experienced troops while Corinne Marik pressed her claim to such worlds as Kalidasa and Stewart, one occupied by the Gryphons and the other the Stewart Dragoons with each proving distinctly unwilling to relinquish them to the Republic.[3]

In late March 3081, ten days after the Republic Formation Treaty was signed, formally establishing the Republic of the Sphere, forces from the Silver Hawks Coalition seized the planet New Hope. The Republic's response was swift; PaladinAlys Rousset-Marik, a strong ally of ExarchDevlin Stone and the Republic's chief advisor on League affairs, had already establised and maintained a number of contingency plans prepared specifically to deal with aggression from the former Free Worlds League region, and on the 3rd of April a number of those plans were activated under the name Operation GOLDEN DAWN.[4]

Operation GOLDEN DAWN saw the Republic launch a substantial counter-attack in three waves, deploying the newly formed regiments of the Republic Auxiliaries - the predecessors to the later Hastati Sentinels and Principes Guards formations - as well as a number of other units. The number of Republic units deployed was substantially greater than the strength of the entire Army of the Marik-Stewart Commonwealth; the Republican units crushed the Silver Hawk Coalition forces already occupying Republic worlds and went on to attack roughly twenty worlds, including worlds from the Marik-Stewart Commonwealth, the Silver Hawks Coalition, the Ohrenson-Zion Province and a number of independent worlds. The campaign was an almost complete success for the Republic, with the Republic seizing Stewart itself after a two-month campaign launched in June 3081. The Silver Hawks Coalition refused to make peace with the Republic, but the Hawks military forces had been comprehensively crushed and the Coalition was served due warning that any attempt to rearm would prompt retaliation from the Republic; the Marik Commonwealth and Stewart Commonality signed peace treaties on the 7th of September, confirming the new Republic border, and began rebuilding.[4]

Corrine's grandson, Anson Marik, attempted to take Stewart from the Republic in 3134, but his invasion failed. He moved the capital from Marik to Atreus in 3136 under threat of invasion from the Lyran Commonwealth. This move proved fortuitous when the Oriente Protectorate launched an invasion of its own soon after that led to the seizure of Marik. Anson also resurrected the Silver Hawk Irregulars, a military force that had been shattered during the Jihad to combat the Lyran invasion when it finally materialized. Coupled with a high-ranking spy, the Commonwealth has so far been able to survive against its larger neighbor.

In August 3137, the Lyran Commonwealth and Clan Wolf invaded the Commonwealth. The Silver Hawk Irregulars began a guerilla warfare campaign against the Lyran incursion which lasted until the Irregulars were effectively wiped-out by the combined Lyran and Clan Wolf forces on Helm. Only 50 to 100 members survived what became known as the Helm Massacre.

On June 5th, 3138 the Lyran & Clan Wolf expedition invaded Stewart. Anson Marik ordered the remaining members of the Silver Hawk Irregulars off-planet to prevent their destruction. Anson was later killed in a running gun battle with Lyran forces in his stronghold.

With no heir to be found and no contingency plans, the Marik-Stewart Commonwealth was decapitated and de facto destroyed by the invasion. It's highly likely that most of its worlds and surviving military units joined the ressurected Free Worlds League pledging their alliegance to Jessica Marik.